Interference in vehicle install

[WX4WCS]

Well I feel like such a noob asking this, but lately I've been having some weird problems with my vehicle install. I have my radio (Kenwood TM-281A) running directly to the battery. There are two other items in my vehicle that are wired to the battery, a GoLight spotlight, and a control panel for emergency lights and an electric horn. When I key the mic on my Kenwood, I can hear the speaker for the horn pop, and the GoLight starts spinning wildly. Is there a way to isolate these items from each other?

 

[mmckenna]

Sounds more like to much RF getting into these other systems.

Check your antenna SWR, make sure it's low. If it's too high, RF can get radiated where you don't want it.

Make sure your coax is run away from the other cabling.

Check your antenna connector.

Doesn't sound like a power issue, but you could try getting a second battery or power supply and running the radio off that. If the issue goes away, then it's something in the power cabling. If it doesn't, it's likely RF related.

And, personally, I'd love to see a video of the Go-Light spinning "wildly", just for giggles.

 

[NDRADIONUT]

Wrap the excess wire from the other 2 devices into small coils CLOSE TO THE DEVICES and tape them up....

 

[WX4WCS]

Sounds good, I'll double check the antenna then. And I'll make sure to grab a video of the light

 

[a417]

mmckenna is correct, this screams RF saturation in the devices.

I'd start looking at your antenna, feedline issues.

 

[WX4WCS]

Yep, I think I had the antenna in a bad spot. It's a magmount that I had close to the front of the roof, once I moved it back to the center all the issues disappeared. I'll investigate a little more and check that the SWR of the antenna is right, but maybe it just came down to bad placement, too close to other wiring or something.

 

[62Scout]

Sounds like you have this licked, as I was about to say that it was likely poor antenna placement as well. I had this exact issue with my Kenwood and GoLights as well in my Grand Cherokee several years ago. Dang lights spun around enough that it eventually broke the control cables going to the Golights (which then resulted in an argument with the Golight rep that insisted that I didn't have the model of light that I said I did, and I've yet to get the cables replaced...but I digress, lol).

Moved the antenna away from the lights, and all was well in the land again

 

[WX4WCS]

Turns out it was the antenna after all. The placement only worked for a little bit, and then the problems came back. Replaced the mount/coax to no avail. As soon as I hooked up an old antenna I had at the house, the problems were solved.

I'll have to take another look at it in the morning, and see if maybe there's an adjustment on it that got messed up. I'd hate to think that the antenna is done for, as I did like the fold over feature on it. For reference, it's a Diamond NR770HNMO, so if anyone has any suggestions as far as adjustments, I'm all ears! Thanks

 

[kayn1n32008]

Turns out it was the antenna after all. The placement only worked for a little bit, and then the problems came back. Replaced the mount/coax to no avail. As soon as I hooked up an old antenna I had at the house, the problems were solved.

I'll have to take another look at it in the morning, and see if maybe there's an adjustment on it that got messed up. I'd hate to think that the antenna is done for, as I did like the fold over feature on it. For reference, it's a Diamond NR770HNMO, so if anyone has any suggestions as far as adjustments, I'm all ears! Thanks

Fold over antennas are ****. As are diamond antennas as are most of the hammy ones from NCG, Comet, Diamond, MFJ.

Stick with Tried and true like Maxrad, Larsen, or PcTel. Depending, seeing the picture of Skywarn(shudder) I'm guessing you live where it is flat, so look for a 5/8 wave.

 

[mmckenna]

For reference, it's a Diamond NR770HNMO, so if anyone has any suggestions as far as adjustments, I'm all ears! Thanks

Ugh. Maybe take it apart and clean all the mating surfaces. Sounds like there is either a corrosion issue or something isn't making good contact.

But I agree with Kayn1n32008, ditch the hammy antennas and get something that will last.

 

[mmckenna]

OK, I found the antenna on the Diamond website.
Remove the set screws that hold the whip into the base. Clean everything really well with a wire brush. Use a small drill bit to clean out the inside of where the whip goes.

Not sure what the fold over mechanism is like, but see if it can be disassembled and clean the mating surfaces of corrosion, rust, etc. Pay close attention to any threaded fasteners, clean them, well also.

Could be an issue with the base coil, too.

Also, check the metal tab in the base of the antenna that contacts the center pin of the NMO mount. Sometimes they can get damaged and not making good contact.

On the other hand, I'd strongly recommend this antenna as a replacement:
http://www.theantennafarm.com/catalog/larsen-nmo2-70b-1712.html
Comparable to what you have, but will likely last a lot longer.

 

[kayn1n32008]

The Larsen NMO 2/70 will outlast the Diamond junk. Had one going on 6 years with out it missing a beat. For your mono band rig, get an Larsen NMO150 5/8wave.

 

[WX4WCS]

Thank you guys for the feedback. I will check over the antenna, clean the contacts, and make sure the set screws are tightened. And I'll definitely look at that Larsen antenna as a replacement soon.

 

[N8RUS]

I had the same Diamond foldover and found the coil full of water after approx. 2.5 yrs of use.

 

[Kb2Jpd]

Well I feel like such a noob asking this, but lately I've been having some weird problems with my vehicle install. I have my radio (Kenwood TM-281A) running directly to the battery. There are two other items in my vehicle that are wired to the battery, a GoLight spotlight, and a control panel for emergency lights and an electric horn. When I key the mic on my Kenwood, I can hear the speaker for the horn pop, and the GoLight starts spinning wildly. Is there a way to isolate these items from each other?

I'd use a NMO mount and a half-wave antenna. The half-wave don't need RF. grounding.

 

[PACNWDude]

I use many Larson, Laird and Antennex NMO whips on several vehicles of mine. The only issues I have had in 16 years has been moisture getting inside and tarnishing the contacts, and the black antennas always lose their paint. Then you have a silver antenna. Now I only buy silver unpainted ones.

Tessco sells them cheap and they work for years. Even commercial magnet mount antennas fails over time. I have yet to have a magnet mount antenna last more than a 2-3 years. I do live near salt water though.

 

[Project25_MASTR]

I use many Larson, Laird and Antennex NMO whips on several vehicles of mine. The only issues I have had in 16 years has been moisture getting inside and tarnishing the contacts, and the black antennas always lose their paint. Then you have a silver antenna. Now I only buy silver unpainted ones.

Tessco sells them cheap and they work for years. Even commercial magnet mount antennas fails over time. I have yet to have a magnet mount antenna last more than a 2-3 years. I do live near salt water though.

I've yet to have any of my black Larsen loosing their coating. Going on about 3 years for my NMO-27B on my XJ. Even the sprung NMO-QB on the roof looks fine. They seem to have a urethane based coating and not a powder coat type finish.

I agree with the commercial grade antennas...also a NMO mount in the roof will further help to separate any RF leakage.

Sent from my SM-T350 using Tapatalk

 

[RFI-EMI-GUY]

Well I feel like such a noob asking this, but lately I've been having some weird problems with my vehicle install. I have my radio (Kenwood TM-281A) running directly to the battery. There are two other items in my vehicle that are wired to the battery, a GoLight spotlight, and a control panel for emergency lights and an electric horn. When I key the mic on my Kenwood, I can hear the speaker for the horn pop, and the GoLight starts spinning wildly. Is there a way to isolate these items from each other?

1) When you say "wired directly to the battery" do you mean the NEGATIVE leads as well? If so, those should be wired to the chassis of the vehicle not to the battery negative terminal.

2) Is the NMO mount drilled into the roof of the vehicle (as Mother M intended) or is it attached to one of those fold over or trunk lid mount widgets. If one of the latter, there's your problem.

 

[AK9R]

I've yet to have any of my black Larsen loosing their coating.

They do. If a black Larsen antenna gets banged onto overhead obstructions (like the bottom of a garage door) enough, the coating will flake off.

All Larsen whips are made of stainless steel wire. They are then plated with copper. The black antenna whips are then coated with a plastic coating...it may be urethane or something proprietary. If you carefully scrape the coating off of a black Larsen antenna whip, you'll find the copper plating. The chrome antenna whips are chromium plated on top of the copper plating (there may be a nickel plating step in there before the chromium).